Conventionally, a stator of a generator or motor includes a hollow cylindrical stator core having a plurality of teeth (magnetic poles) radially arranged and projecting radially inward and a plurality of slots open between adjacent ones of the teeth, and a stator coil assembled with the core by accommodating coil side parts into the slots. Concerning the assembling of a stator coil, a so-called inserter method for fabricating the stator coil separately from a stator core in advance and, thereafter, accommodating this coil into each slot of the core is known (see, JP2000-245120A).
A coil used in this inserter method is known to be formed into a track shape by annularly winding a wire and have straight parts on both sides accommodated into slots of a stator core. In the stator coil inserted into the slots, parts that are accommodated in the slots serve as coil side parts and the remaining parts of the coil projecting from end surfaces of the stator core without being inserted into the slots serve as coil end parts.